org.apache.drill.exec.physical.impl.scan.framework

Interface ManagedScanFramework.ReaderFactory

All Known Implementing Classes:

BasicScanFactory, FileScanFramework.FileReaderFactory, HDF5FormatPlugin.HDF5ReaderFactory, ShpFormatPlugin.ShpReaderFactory, XMLFormatPlugin.XMLReaderFactory

Enclosing class:

ManagedScanFramework

public static interface ManagedScanFramework.ReaderFactory

Creates a batch reader on demand. Unlike earlier versions of Drill, this framework creates readers one by one, when they are needed. Doing so avoids excessive resource demands that come from creating potentially thousands of readers up front.

The reader itself is unique to each file type. This interface provides a common interface that this framework can use to create the file-specific reader on demand.

Also manages opening the reader using a scan-specific schema negotiator.

Method Summary

Modifier and Type	Method and Description
void	bind(ManagedScanFramework framework)
ManagedReader<? extends SchemaNegotiator>	next()

Method Detail

bind

void bind(ManagedScanFramework framework)

next

ManagedReader<? extends SchemaNegotiator> next()